Albumin-Leaking Membranes: Friends or Foes?

Hemodialysis (HD) is one of the major treatment modalities for patients with kidney failure; moreover, there are many alternatives, such as expanded HD (HDx) and on-line hemodiafiltration (HDF). This chapter begins with a historical overview of these treatment modalities and discusses the current mainstream treatments in Europe, North America, and Japan. The "protein-losing" dialysis membrane was first realized in Japan in the early 1980s, and treatment using these membranes has evolved into HDx and/or on-line HDF with an albumin leakage range of 3-6 g, which corresponds to a 30-40% reduction rate in α1-microglobulin levels over the course of a single dialysis session that reduces or eliminates many clinical symptoms. Whether albumin-leaking membranes are "friends or foes" depends on the patient's general conditions; however, based on our more than 40 years of clinical experience in Japan, they are generally considered "friends."